<!DOCTYPE html>
<html>

<head>
    <meta http-equiv="Content-type" content="text/html; charset=utf-8" />
    <title></title>
    <script src="http://code.jquery.com/jquery-1.11.3.js"></script>
</head>

<body>
	<div>元素一</div>
	<div>元素二</div>
	<div>元素三</div>
    
    <script type="text/javascript">
    	//var div = document.getElementsByTagName('div');
		var $div = $('div'); //jQuery对象
		//var div = $div.get(0);
		var div = $div.first();
		div.css('color','red'); //操作dom对象的属性
    </script>
    
</body>

</html>